diff options
Diffstat (limited to 'drivers/iio/light/veml6075.c')
| -rw-r--r-- | drivers/iio/light/veml6075.c | 474 |
1 files changed, 474 insertions, 0 deletions
diff --git a/drivers/iio/light/veml6075.c b/drivers/iio/light/veml6075.c new file mode 100644 index 0000000000..05d4c0e901 --- /dev/null +++ b/drivers/iio/light/veml6075.c @@ -0,0 +1,474 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Vishay VEML6075 UVA and UVB light sensor + * + * Copyright 2023 Javier Carrasco <javier.carrasco.cruz@gmail.com> + * + * 7-bit I2C slave, address 0x10 + */ + +#include <linux/bitfield.h> +#include <linux/delay.h> +#include <linux/err.h> +#include <linux/i2c.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/regmap.h> +#include <linux/units.h> + +#include <linux/iio/iio.h> + +#define VEML6075_CMD_CONF 0x00 /* configuration register */ +#define VEML6075_CMD_UVA 0x07 /* UVA channel */ +#define VEML6075_CMD_UVB 0x09 /* UVB channel */ +#define VEML6075_CMD_COMP1 0x0A /* visible light compensation */ +#define VEML6075_CMD_COMP2 0x0B /* infrarred light compensation */ +#define VEML6075_CMD_ID 0x0C /* device ID */ + +#define VEML6075_CONF_IT GENMASK(6, 4) /* intregration time */ +#define VEML6075_CONF_HD BIT(3) /* dynamic setting */ +#define VEML6075_CONF_TRIG BIT(2) /* trigger */ +#define VEML6075_CONF_AF BIT(1) /* active force enable */ +#define VEML6075_CONF_SD BIT(0) /* shutdown */ + +#define VEML6075_IT_50_MS 0x00 +#define VEML6075_IT_100_MS 0x01 +#define VEML6075_IT_200_MS 0x02 +#define VEML6075_IT_400_MS 0x03 +#define VEML6075_IT_800_MS 0x04 + +#define VEML6075_AF_DISABLE 0x00 +#define VEML6075_AF_ENABLE 0x01 + +#define VEML6075_SD_DISABLE 0x00 +#define VEML6075_SD_ENABLE 0x01 + +/* Open-air coefficients and responsivity */ +#define VEML6075_A_COEF 2220 +#define VEML6075_B_COEF 1330 +#define VEML6075_C_COEF 2950 +#define VEML6075_D_COEF 1740 +#define VEML6075_UVA_RESP 1461 +#define VEML6075_UVB_RESP 2591 + +static const int veml6075_it_ms[] = { 50, 100, 200, 400, 800 }; + +struct veml6075_data { + struct i2c_client *client; + struct regmap *regmap; + /* + * prevent integration time modification and triggering + * measurements while a measurement is underway. + */ + struct mutex lock; +}; + +/* channel number */ +enum veml6075_chan { + CH_UVA, + CH_UVB, +}; + +static const struct iio_chan_spec veml6075_channels[] = { + { + .type = IIO_INTENSITY, + .channel = CH_UVA, + .modified = 1, + .channel2 = IIO_MOD_LIGHT_UVA, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), + .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME), + }, + { + .type = IIO_INTENSITY, + .channel = CH_UVB, + .modified = 1, + .channel2 = IIO_MOD_LIGHT_UVB, + .info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | + BIT(IIO_CHAN_INFO_SCALE), + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), + .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME), + }, + { + .type = IIO_UVINDEX, + .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), + .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_INT_TIME), + .info_mask_shared_by_all_available = BIT(IIO_CHAN_INFO_INT_TIME), + }, +}; + +static int veml6075_request_measurement(struct veml6075_data *data) +{ + int ret, conf, int_time; + + ret = regmap_read(data->regmap, VEML6075_CMD_CONF, &conf); + if (ret < 0) + return ret; + + /* disable shutdown and trigger measurement */ + ret = regmap_write(data->regmap, VEML6075_CMD_CONF, + (conf | VEML6075_CONF_TRIG) & ~VEML6075_CONF_SD); + if (ret < 0) + return ret; + + /* + * A measurement requires between 1.30 and 1.40 times the integration + * time for all possible configurations. Using a 1.50 factor simplifies + * operations and ensures reliability under all circumstances. + */ + int_time = veml6075_it_ms[FIELD_GET(VEML6075_CONF_IT, conf)]; + msleep(int_time + (int_time / 2)); + + /* shutdown again, data registers are still accessible */ + return regmap_update_bits(data->regmap, VEML6075_CMD_CONF, + VEML6075_CONF_SD, VEML6075_CONF_SD); +} + +static int veml6075_uva_comp(int raw_uva, int comp1, int comp2) +{ + int comp1a_c, comp2a_c, uva_comp; + + comp1a_c = (comp1 * VEML6075_A_COEF) / 1000U; + comp2a_c = (comp2 * VEML6075_B_COEF) / 1000U; + uva_comp = raw_uva - comp1a_c - comp2a_c; + + return clamp_val(uva_comp, 0, U16_MAX); +} + +static int veml6075_uvb_comp(int raw_uvb, int comp1, int comp2) +{ + int comp1b_c, comp2b_c, uvb_comp; + + comp1b_c = (comp1 * VEML6075_C_COEF) / 1000U; + comp2b_c = (comp2 * VEML6075_D_COEF) / 1000U; + uvb_comp = raw_uvb - comp1b_c - comp2b_c; + + return clamp_val(uvb_comp, 0, U16_MAX); +} + +static int veml6075_read_comp(struct veml6075_data *data, int *c1, int *c2) +{ + int ret; + + ret = regmap_read(data->regmap, VEML6075_CMD_COMP1, c1); + if (ret < 0) + return ret; + + return regmap_read(data->regmap, VEML6075_CMD_COMP2, c2); +} + +static int veml6075_read_uv_direct(struct veml6075_data *data, int chan, + int *val) +{ + int c1, c2, ret; + + guard(mutex)(&data->lock); + + ret = veml6075_request_measurement(data); + if (ret < 0) + return ret; + + ret = veml6075_read_comp(data, &c1, &c2); + if (ret < 0) + return ret; + + switch (chan) { + case CH_UVA: + ret = regmap_read(data->regmap, VEML6075_CMD_UVA, val); + if (ret < 0) + return ret; + + *val = veml6075_uva_comp(*val, c1, c2); + return IIO_VAL_INT; + case CH_UVB: + ret = regmap_read(data->regmap, VEML6075_CMD_UVB, val); + if (ret < 0) + return ret; + + *val = veml6075_uvb_comp(*val, c1, c2); + return IIO_VAL_INT; + default: + return -EINVAL; + } +} + +static int veml6075_read_int_time_index(struct veml6075_data *data) +{ + int ret, conf; + + ret = regmap_read(data->regmap, VEML6075_CMD_CONF, &conf); + if (ret < 0) + return ret; + + return FIELD_GET(VEML6075_CONF_IT, conf); +} + +static int veml6075_read_int_time_ms(struct veml6075_data *data, int *val) +{ + int int_index; + + guard(mutex)(&data->lock); + int_index = veml6075_read_int_time_index(data); + if (int_index < 0) + return int_index; + + *val = veml6075_it_ms[int_index]; + + return IIO_VAL_INT; +} + +static int veml6075_get_uvi_micro(struct veml6075_data *data, int uva_comp, + int uvb_comp) +{ + int uvia_micro = uva_comp * VEML6075_UVA_RESP; + int uvib_micro = uvb_comp * VEML6075_UVB_RESP; + int int_index; + + int_index = veml6075_read_int_time_index(data); + if (int_index < 0) + return int_index; + + switch (int_index) { + case VEML6075_IT_50_MS: + return uvia_micro + uvib_micro; + case VEML6075_IT_100_MS: + case VEML6075_IT_200_MS: + case VEML6075_IT_400_MS: + case VEML6075_IT_800_MS: + return (uvia_micro + uvib_micro) / (2 << int_index); + default: + return -EINVAL; + } +} + +static int veml6075_read_uvi(struct veml6075_data *data, int *val, int *val2) +{ + int ret, c1, c2, uva, uvb, uvi_micro; + + guard(mutex)(&data->lock); + + ret = veml6075_request_measurement(data); + if (ret < 0) + return ret; + + ret = veml6075_read_comp(data, &c1, &c2); + if (ret < 0) + return ret; + + ret = regmap_read(data->regmap, VEML6075_CMD_UVA, &uva); + if (ret < 0) + return ret; + + ret = regmap_read(data->regmap, VEML6075_CMD_UVB, &uvb); + if (ret < 0) + return ret; + + uvi_micro = veml6075_get_uvi_micro(data, veml6075_uva_comp(uva, c1, c2), + veml6075_uvb_comp(uvb, c1, c2)); + if (uvi_micro < 0) + return uvi_micro; + + *val = uvi_micro / MICRO; + *val2 = uvi_micro % MICRO; + + return IIO_VAL_INT_PLUS_MICRO; +} + +static int veml6075_read_responsivity(int chan, int *val, int *val2) +{ + /* scale = 1 / resp */ + switch (chan) { + case CH_UVA: + /* resp = 0.93 c/uW/cm2: scale = 1.75268817 */ + *val = 1; + *val2 = 75268817; + return IIO_VAL_INT_PLUS_NANO; + case CH_UVB: + /* resp = 2.1 c/uW/cm2: scale = 0.476190476 */ + *val = 0; + *val2 = 476190476; + return IIO_VAL_INT_PLUS_NANO; + default: + return -EINVAL; + } +} + +static int veml6075_read_avail(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + const int **vals, int *type, int *length, + long mask) +{ + switch (mask) { + case IIO_CHAN_INFO_INT_TIME: + *length = ARRAY_SIZE(veml6075_it_ms); + *vals = veml6075_it_ms; + *type = IIO_VAL_INT; + return IIO_AVAIL_LIST; + + default: + return -EINVAL; + } +} + +static int veml6075_read_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int *val, int *val2, long mask) +{ + struct veml6075_data *data = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_RAW: + return veml6075_read_uv_direct(data, chan->channel, val); + case IIO_CHAN_INFO_PROCESSED: + return veml6075_read_uvi(data, val, val2); + case IIO_CHAN_INFO_INT_TIME: + return veml6075_read_int_time_ms(data, val); + case IIO_CHAN_INFO_SCALE: + return veml6075_read_responsivity(chan->channel, val, val2); + default: + return -EINVAL; + } +} + +static int veml6075_write_int_time_ms(struct veml6075_data *data, int val) +{ + int i = ARRAY_SIZE(veml6075_it_ms); + + guard(mutex)(&data->lock); + + while (i-- > 0) { + if (val == veml6075_it_ms[i]) + break; + } + if (i < 0) + return -EINVAL; + + return regmap_update_bits(data->regmap, VEML6075_CMD_CONF, + VEML6075_CONF_IT, + FIELD_PREP(VEML6075_CONF_IT, i)); +} + +static int veml6075_write_raw(struct iio_dev *indio_dev, + struct iio_chan_spec const *chan, + int val, int val2, long mask) +{ + struct veml6075_data *data = iio_priv(indio_dev); + + switch (mask) { + case IIO_CHAN_INFO_INT_TIME: + return veml6075_write_int_time_ms(data, val); + default: + return -EINVAL; + } +} + +static const struct iio_info veml6075_info = { + .read_avail = veml6075_read_avail, + .read_raw = veml6075_read_raw, + .write_raw = veml6075_write_raw, +}; + +static bool veml6075_readable_reg(struct device *dev, unsigned int reg) +{ + switch (reg) { + case VEML6075_CMD_CONF: + case VEML6075_CMD_UVA: + case VEML6075_CMD_UVB: + case VEML6075_CMD_COMP1: + case VEML6075_CMD_COMP2: + case VEML6075_CMD_ID: + return true; + default: + return false; + } +} + +static bool veml6075_writable_reg(struct device *dev, unsigned int reg) +{ + switch (reg) { + case VEML6075_CMD_CONF: + return true; + default: + return false; + } +} + +static const struct regmap_config veml6075_regmap_config = { + .name = "veml6075", + .reg_bits = 8, + .val_bits = 16, + .max_register = VEML6075_CMD_ID, + .readable_reg = veml6075_readable_reg, + .writeable_reg = veml6075_writable_reg, + .val_format_endian = REGMAP_ENDIAN_LITTLE, +}; + +static int veml6075_probe(struct i2c_client *client) +{ + struct veml6075_data *data; + struct iio_dev *indio_dev; + struct regmap *regmap; + int config, ret; + + indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data)); + if (!indio_dev) + return -ENOMEM; + + regmap = devm_regmap_init_i2c(client, &veml6075_regmap_config); + if (IS_ERR(regmap)) + return PTR_ERR(regmap); + + data = iio_priv(indio_dev); + data->client = client; + data->regmap = regmap; + + mutex_init(&data->lock); + + indio_dev->name = "veml6075"; + indio_dev->info = &veml6075_info; + indio_dev->channels = veml6075_channels; + indio_dev->num_channels = ARRAY_SIZE(veml6075_channels); + indio_dev->modes = INDIO_DIRECT_MODE; + + ret = devm_regulator_get_enable(&client->dev, "vdd"); + if (ret < 0) + return ret; + + /* default: 100ms integration time, active force enable, shutdown */ + config = FIELD_PREP(VEML6075_CONF_IT, VEML6075_IT_100_MS) | + FIELD_PREP(VEML6075_CONF_AF, VEML6075_AF_ENABLE) | + FIELD_PREP(VEML6075_CONF_SD, VEML6075_SD_ENABLE); + ret = regmap_write(data->regmap, VEML6075_CMD_CONF, config); + if (ret < 0) + return ret; + + return devm_iio_device_register(&client->dev, indio_dev); +} + +static const struct i2c_device_id veml6075_id[] = { + { "veml6075" }, + { } +}; +MODULE_DEVICE_TABLE(i2c, veml6075_id); + +static const struct of_device_id veml6075_of_match[] = { + { .compatible = "vishay,veml6075" }, + {} +}; +MODULE_DEVICE_TABLE(of, veml6075_of_match); + +static struct i2c_driver veml6075_driver = { + .driver = { + .name = "veml6075", + .of_match_table = veml6075_of_match, + }, + .probe = veml6075_probe, + .id_table = veml6075_id, +}; + +module_i2c_driver(veml6075_driver); + +MODULE_AUTHOR("Javier Carrasco <javier.carrasco.cruz@gmail.com>"); +MODULE_DESCRIPTION("Vishay VEML6075 UVA and UVB light sensor driver"); +MODULE_LICENSE("GPL"); |